Chemical constituents of Habenaria petalodes Lindl. (Orchidaceae)

Abstract

Uma nova substância, denominada habenariosídeo {[(2R)-2-[(2,3,4,6-tetra-O-acetil-b-Dglicopiranosil)oxi]-2-(2-metilpropil)-1,4-dioxo-1,4-butanodiil]bis(oximetileno-4,1-fenileno) bis-b-D-glicopiranosídeo}, foi isolada das frações polares do extrato etanólico de Habenaria petalodes Lindl. (Orchidaceae), juntamente com duas substâncias conhecidas e estruturalmente relacionadas, a loroglossina e a militarina. Os flavonóides: isoquercitrina, isorramnetina 3-O-b-D-glicopiranosídeo e isorramnetina 3,7-di-O-b-D-glicopiranosídeo, também foram isolados. As estruturas do habenariosídeo e das demais substâncias foram determinadas pela análise dos dados de EM, IV, UV e RMN mono e bidimensional e comparação com os dados publicados na literatura. IntroductionThe Brazilian flora is exceedingly rich and comprises more than 56,000 endemic plant species. Among the 22,000 members of the family Orchidaceae that have been described worldwide, approximately 1,800 grow endemically in Brazil. 1 In spite of its size and diversity when compared with other plant families, a relatively small number of orchid species have been investigated regarding their chemical composition, with about 300 secondary metabolites reported so far. These included, among others, flavonoids, terpenoids, quinones, phenanthrenes, stilbenes, lignans, and glucosylated benzyl esters of succinic, malic, tartaric and citric acids. [2][3][4][5][6] The phytochemical investigations of Brazilian Orchidaceae are also restricted to few published works: a report concerning the presence of methylated C-glycosylflavones as taxonomic markers in fifteen orchids, 7 and the investigation of the floral composition of other twenty-one species. 8 The genus Habenaria (Orchidaceae) comprises over 600 species of which around 170 occur in Brazil. 9 However, to the best of our knowledge only Habenaria repens Nutt. was chemically investigated so far, resulting in the identification of habenariol, a compound with potent feeding deterrent activity. [10][11][12] In the present paper we report the first phytochemical investigation of Habenaria petalodes Lindl., describing the isolation and structure elucidation of six compounds (1-6), including a new 2-malic acid derivative (4) denominated habenarioside. Cota et al. 1099 Vol. 19, No. 6, 2008 Results and DiscussionThe whole plant was extracted by maceration with ethanol and the extract was subjected to liquid-liquid partition between CH 2 Cl 2 and MeOH:H 2 O (1:1) to afford an organic and a hydroalcoholic fraction. The latter was subjected to solid phase extraction (SFE) using RP-18 cartridges followed by semi-preparative RP-HPLC to yield six compounds (Figure 1-2).The ESI-MS of compounds 1 and 5 exhibited quasimolecular ion peaks ([M + Na] + ) at m/z 765 and m/z 749, respectively. Their molecular weight, together with their UV, 1 H and 13 C NMR data were in accordance with those reported for loroglossin (1) and militarin (5). 5,14 Habenarioside (4) which was given the trivial name habenarioside as it is a mono-glucosylated derivative of hab...

Contribution of militarine and dactylorhin A to the plant growth‐inhibitory activity of a weed‐suppressing orchid, Bletilla striata

“…The anomeric configuration was regarded as b from the J-value (7.3 Hz) of the glucosyl, H-1. The positions of the glucose moieties were deduced to be C-5′ and 5″ from the correlation between glucosyl H-1 and C-5′ and 5″ in the 2D NMR heteronuclear multiple bond correlation (HMBC) data.As all the spectroscopic data, including the optical rotation, agreed with the reported data, 1 was identified as militarine (Aasen et al 1975;Cota et al 2008) (Fig. 2).…”

“…As all the spectroscopic data, including the optical rotation, agreed with the reported data, 1 was identified as militarine (Aasen et al . 1975; Cota et al . 2008) (Fig.…”

Metabolomic Analysis of a Commercially Important Aromatic Plant from the Indian Ocean: Vanilla planifolia

“…They suggested that this Tokoro et al (1990) and Kanisawa (1993;Kanisawa et al, 1994) isolated the most abundant glucosides from green pods and identified them as glucovanillin, p-hydroxybenzyl alcohol glucoside, bis[4-(β-D-glucopyranosyloxy)-benzyl]-2-isopropyltartrate (glucoside A) and bis[4-(β-D-glucopyranosyloxy)-benzyl]-2-(2-butyl)-tartrate (glucoside B). These glucosides A and B were reported for the first time in vanilla and have a structure very similar to the loroglossins found in other Orchidaceae plants (Cota et al, 2008;Huang et al, 2004). Various other minor glucosides were identified after enzymatic hydrolysis: glucosides of vanillic acid, vanillyl alcohol, p-vinyl-guaiacol, acetovanillon, caffeic acid, ferulic acid, methyl-3,4-dihydroxycinnamic acid, 2-methoxy-4-cresol, homovanillyl alcohol, 3,4-dihydroxybenzoic acid, ethyl-4-hydroxy-3-methoxyphenylacetate, p-cresol, p-vinylphenol, methylsalicylate, p-hydroxybenzylethyl ether, p-hydroxybenzaldehyde, p-hydroxy cinnamic acid, cinnamic alcohol, cinnamic acid, phenethyl alcohol, 3-phenylpropanol (Kanisawa et al, 1994).…”

Chemical constituents and leishmanicidal activity from leaves of Kielmeyera variabilis

“…Characterization of the sugar moieties from the mixture of quercetin 3-β-galactopyranoside (1) and quercetin 3-β-glucopyranoside (2) was performed according Cota et al 2008b.…”